1. Field of the Invention
The present invention relates to a tape rule. More particularly, the present invention relates to an error proof measuring tape rule.
2. Description of the Prior Art
Tape rulers are widely used in engineering and construction fields. Millions of people use tape rules to do their measuring job everyday. Thousand of tape rule factories produce tape rules worldwide.
All the tape rules, however, contain the same defect; the end part of the tape rules are made with a hook to hook onto the job being measured that is either of the loose type or the fixed type and which is fitted on the steel tape with rivets. Some have a reinforced steel plate added.
When the tape rule is used to measure long section material like angle bars, hollow sections, or I beams, the tape rule always hooks on the rivet, not the hook, especially, material with sharp edges. This defect results in the work being cut shorter than the reading and appears on all the tape rules available on the market.
This defect is exemplified by putting a razor sharp knife 45 degrees slantingly, pulling the tape rule slowly towards the razor sharp knife; the tape rule will stop at the point of the rivet head, regardless how thin the rivet is made. This experiment tells us that all of the tape rules have the same defect.
When these types of tape rule are used to measure jobs, there is the risk of a measuring mistake; the user always has to approach the end of the material and check whether the hook is properly hooked at the end of the job being measured, which causes wasted time.
Numerous innovations for tape rules have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
FOR EXAMPLE, U.S. Pat. No. 3,745,663 to Dodge teaches a measuring device comprising a conventional, metal measuring tape including a hook member adapted to be connected to the outer free end of the tape and having an arcuate shape corresponding with the shape of a cylindrical member which is to be measured. The hook member is located so that its center of curvature is aligned with the zero point of the tape. An arm assembly is carried on the tape housing for pivotal movement about the longitudinal axis of the tape. A surface of the arm is arranged to extend exactly perpendicular to the tape axis to serve as a measuring datum.
ANOTHER EXAMPLE, U.S. Pat. No. 4,300,289 to DeHaven teaches a hook end for attachment to the free end of a graduated measuring tape, especially adapted to replace a broken free end.
STILL ANOTHER EXAMPLE, U.S. Pat. No. 4,930,227 to Ketchpel teaches a spring powered coilable rule that has a coilable metal tape with a tape hook at the end thereof. The tape hook has an elongated body portion extending along the surface of the tape a length greater than the width of the tape and a depending leg portion which has an upper end dimensioned and configured to overlie the outer edge of the tape in its uncoiled state. The body portion tapers in width from the leg portion to a reduced width, and at least three rivets are spaced axially along the length of the body portion to secure the tape hook to the tape.
YET ANOTHER EXAMPLE, U.S. Pat. No. 5,010,656 to Broselow teaches an apparatus for therapeutic treatment of a patient. A measuring tape is used to measure the heel-to-crown height of a patient. The tape has coded zones along its effective length. A dispenser is provided with correspondingly coded zones whereby a treatment administered using the coding of the dispenser is correlated to the heel-to-crown height of a patient as measured by the tape.
FINALLY, STILL YET ANOTHER EXAMPLE, U.S. Pat. No. 5,214,859 to Buhler teaches that the leading end of a tape measure can be pushed over an uneven surface such as a shingled roof by coupling a sled or ski to the end of the tape. The sled has a smooth lower surface. A forward end of the sled is upraised to as to present a curved surface to obstacles. As the tape is pushed along the surface, the sled is pushed by the tape. The sled prevents the end of the tape from snagging on objects, by gliding over obstacles.
It is apparent that numerous innovations for tape rules have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.